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GCSE AQA Physics Unit 2 Exam - 19th/May

Reply 60

irMike

5

Original post by klodian12

What did you guys put for the question where it asked if it was friction or weight?

Weight, because friction acts against movement. I wasn't sure whether it was Weight or Gravity though

Reply 61

AlphaMolecule

4

Original post by jshep000

J was the lowest mass therefore it was the right answer. and I put 6 days.. because you can't really get 6.2 days, so I'm quite confident I will get the marks for putting 6 days tbh. what did everyone get on P3 for the boat ultrasound question it was the second question?

0.5 * 1600 * 0.8 = 640 metres

Reply 62

yeyhelloxoxoxo

2

Original post by alphanick

i put j, since stars smaller than or similar-size to the sun become black dwarfs eventually. Larger stars tend to become supernovas followed by black holes or neutron stars.

yay! Thank you :d

Reply 63

jshep000

15

Original post by AlphaNick

0.5 * 1600 * 0.8 = 640 metres

oh i got 1.6 x 1600 I don't know why :frown:

2560 fml. was it gravity causing the satellite to have centripetal force towards the earth?

Reply 64

Messorem235

I found it reasonably easy in general.

However, I was a bit lost on the 6 markers on the forces, the three options for the force going in the direction of the cyclist's motion were 'gravity, weight and friction', I picked friction because surely gravity and gravity and weight are forces going downwards so friction was the only one left? Did anyone else say friction? Also it did say the road was straight and level right? No hills? Because I put the velocity changed because there was less air resistance between X and Y and then more resistance between Y and Z, hence the change in velocity. But some people say gravitational potential because he was on a hill to begin with. I could have sworn it did say straight and level?

What's the consensus on this question then?

Reply 65

AlphaMolecule

4

Original post by jshep000

oh i got 1.6 x 1600 I don't know why :frown:

2560 fml. was it gravity causing the satellite to have centripetal force towards the earth?

Yeah gravity provided the centripetal force.

Reply 66

georgie1997

7

Original post by mickel_w

thats what I guessed because I ran out of time, it's wrong though :tongue:

you still get a mark for putting the right formula down *I think*

We used the correct first equation, we just divided it by the wrong mass so we will still get 1 make :smile:

Reply 67

jshep000

15

also for the bike question, what was A and B? for A i put friction, for B I put air resistance? o.o

Reply 68

georgie1997

7

What did everyone say for the 6 mark question ? (P2)

Reply 69

klodian12

Original post by jshep000

also for the bike question, what was A and B? for A i put friction, for B I put air resistance? o.o

I put weight

Reply 70

AlphaMolecule

4

Original post by Messorem235

I found it reasonably easy in general.

However, I was a bit lost on the 6 markers on the forces, the three options for the force going in the direction of the cyclist's motion were 'gravity, weight and friction', I picked friction because surely gravity and gravity and weight are forces going downwards so friction was the only one left? Did anyone else say friction? Also it did say the road was straight and level right? No hills? Because I put the velocity changed because there was less air resistance between X and Y and then more resistance between Y and Z, hence the change in velocity. But some people say gravitational potential because he was on a hill to begin with. I could have sworn it did say straight and level?

What's the consensus on this question then?

I think, to be honest, it was just a classic terminal velocity question.

My (roughly) 6 points were:
- biker exerts force on pedals at beginning, this exerts a reaction force against friction which moves him forwards
- since he has been / is moving at a low speed, the amount of air particles hitting him is low
- at this point in time, the forward force is greater than air resistance - causing acceleration
- as his speed increases, the air resistance force increases, causing a lower resultant force overall
- this reduces the rate of change of velocity, meaning that he accelerates slower and the graphs plateaus
- at point Z, the size of air resistance = the size of the forward force, so he moves at a constant speed

Reply 71

jshep000

15

Original post by klodian12

I put weight

weight is a downwards force though isnt it?

Reply 72

klodian12

Original post by jshep000

weight is a downwards force though isnt it?

I thought that It couldn't be friction as friction doesn't act In that direction but I think I'm wrong

Reply 73

zoe_macpherson

Original post by Dinaa

How was it guys !?? :wink:

Didn't find it as bad as I thought it would be, got a bit stuck on the stars pages but managed to come up with answers, feel a lot better now than before the exam!

Reply 74

sophiewantstheA*

Original post by jshep000

also for the bike question, what was A and B? for A i put friction, for B I put air resistance? o.o

I put the same as you ☺️

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Reply 75

yamyam77

3

js on the velocity question it said he was cycling at a constant speed so he cant of sped up, it must of been something to do with weather and increased air resistance due to it